Mechanisms for LAA/LTE-U detection to mitigate impact on Wi-Fi performance

ABSTRACT

A wireless communication device may conduct first wireless communications over a first frequency band according to a first radio access technology (RAT), and may detect second wireless communications conducted over the first frequency band according to a second RAT while the wireless communication device is conducting the first wireless communications. The wireless communication device may then adjust characteristics and/or parameters associated with the first wireless communications based on the detected second wireless communications. In a specific example, a wireless communication device conducting Wi-Fi communications in the 5 GHz band may detect cellular communications (e.g. LAA/LTE-U communications) also conducted in the 5 GHz band while the wireless communication device is conducting the Wi Fi communications. The wireless communication device may then adjust characteristics and/or parameters associated with its Wi-Fi communications based on the detected signals/frequencies of the cellular (LAA/LTE-U) communications.

PRIORITY CLAIM

This application claims benefit of priority of U.S. Provisional PatentApplication Ser. No. 62/301,419 titled “Mechanisms for LAA/LTE-UDetection to Mitigate Impact on Wi-Fi Performance”, filed on Feb. 29,2016, which is hereby incorporated by reference as though fully andcompletely set forth herein.

FIELD OF THE INVENTION

The present application relates to wireless communications, and moreparticularly to mitigating the effects of LAA/LTE-U transmissions onWi-Fi communications.

DESCRIPTION OF THE RELATED ART

Wireless communication systems are rapidly growing in usage. In recentyears, wireless devices such as smart phones and tablet computers havebecome increasingly sophisticated. In addition to supporting telephonecalls, many mobile devices (i.e., user equipment devices or UEs) nowprovide access to the internet, email, text messaging, and navigationusing the global positioning system (GPS), and are capable of operatingsophisticated applications that utilize these functionalities.Additionally, there exist numerous different wireless communicationtechnologies and standards. Some examples of wireless communicationstandards include GSM, UMTS (WCDMA, TDS-CDMA), LTE, LTE Advanced(LTE-A), HSPA, 3GPP2 CDMA2000 (e.g., 1×RTT, 1×EV-DO, HRPD, eHRPD), IEEE802.11 (WLAN or Wi-Fi), IEEE 802.16 (WiMAX), BLUETOOTH™, etc.

The ever increasing number of features and functionality introduced inwireless communication devices also creates a continuous need forimprovement in both wireless communications and in wirelesscommunication devices. In particular, it is important to ensure theaccuracy of transmitted and received signals through user equipment (UE)devices, e.g., through wireless devices such as cellular phones, basestations and relay stations used in wireless cellular communications. Inaddition, increasing the functionality of a UE device can place asignificant strain on the battery life of the UE device. Thus it is veryimportant to also reduce power requirements in UE device designs whileallowing the UE device to maintain good transmit and receive abilitiesfor improved communications.

The UEs, which may be mobile telephones or smart phones, portable gamingdevices, laptops, wearable devices, PDAs, tablets, portable Internetdevices, music players, data storage devices, or other handheld devices,etc. may have multiple radio interfaces that enable support of multipleradio access technologies (RATs) as defined by the various wirelesscommunication standards (LTE, LTE-A, Wi-Fi, BLUETOOTH™, etc.). The radiointerfaces may be used by various applications and the presence of themultiple radio interfaces may necessitate the UE to implement mobilitysolutions to seamlessly run applications simultaneously over multipleradio interfaces (e.g., over LTE/LTE-A and BLUETOOTH™) without impactingthe end-to-end performance of the application. That is, the UE may needto implement mobility solutions to simultaneously operate multiple radiointerfaces corresponding to multiple RATs (e.g., LTE/LTE-A andBLUETOOTH™).

In addition to the communication standards mentioned above, there alsoexist extensions aimed at boosting transmission coverage in certaincellular networks. For example, LTE in Unlicensed spectrum (LTE-U)allows cellphone carriers to boost coverage in their cellular networksby transmitting in the unlicensed 5 GHz band which is also used by manyWi-Fi devices. License Assisted Access (LAA) describes a similartechnology aimed to standardize operation of LTE in the Wi-Fi bandsthrough the use of a contention protocol referred to aslisten-before-talk (LBT), which facilitates coexistence with other Wi-Fidevices on the same band. However, the coexistence of cellular and Wi-Ficommunications in the same band can still result in the degradation ofdata throughput and/or decreased performance of streaming applications(data streaming) when both Wi-Fi signals and LAA/LTE-U signals arepresent.

SUMMARY OF THE INVENTION

Embodiments are presented herein of, inter alia, of methods fordetecting LAA/LTE-U signals when performing Wi-Fi communications, andmitigating the impact of those LAA/LTE-U signals on the Wi-Ficommunications. Embodiments are further presented herein for wirelesscommunication systems containing user equipment (UE) devices and/or basestations and access points (APs) communicating with each other withinthe wireless communication systems.

In some embodiments, a wireless communication device may conduct firstwireless communications over a first frequency band according to a firstradio access technology (RAT), and may also detect—while conducting thefirst wireless communications—second wireless communications conductedover the first frequency band according to a second RAT. The wirelesscommunication device may then adjust characteristics and/or parametersassociated with the first wireless communications in response to andbased on at least the detected second wireless communications. Forexample, in various embodiments, a wireless communication deviceconducting Wi-Fi communications in the 5 GHz band may detect cellularcommunications (e.g. LAA/LTE-U communications) also conducted in the 5GHz band while the wireless communication device is conducting the Wi-Ficommunications. The wireless communication device may then adjustcharacteristics and/or parameters associated with its Wi-Ficommunications based at least on the detected signals/frequencies of thecellular (LAA/LTE-U) communications.

Note that the techniques described herein may be implemented in and/orused with a number of different types of devices, including but notlimited to, base stations, access points, cellular phones, portablemedia players, tablet computers, wearable devices, and various othercomputing devices.

This Summary is intended to provide a brief overview of some of thesubject matter described in this document. Accordingly, it will beappreciated that the above-described features are merely examples andshould not be construed to narrow the scope or spirit of the subjectmatter described herein in any way. Other features, aspects, andadvantages of the subject matter described herein will become apparentfrom the following Detailed Description, Figures, and Claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an exemplary (and simplified) wireless communicationsystem, according to some embodiments;

FIG. 2 illustrates an exemplary base station in communication with anexemplary wireless user equipment (UE) device, according to someembodiments;

FIG. 3 illustrates an exemplary block diagram of a UE, according to someembodiments;

FIG. 4 illustrates an exemplary block diagram of a base station,according to some embodiments;

FIG. 5 illustrates an exemplary wireless communication system, accordingto some embodiments;

FIG. 6 shows an exemplary communication system in which multipledifferent devices may communicate with each other over a specific band,such as 2.4 GHz and/or 5 GHz frequency bands using Wi-Fi;

FIG. 7 shows an example of typical License Assisted Access (LAA) controland data scheduling;

FIG. 8 shows an exemplary flowchart for Listen Before Talk (LBT)procedures;

FIG. 9 shows a table with exemplary values for various parameters forLAA LBT;

FIG. 10 shows a table with exemplary values for various parameters forWi-Fi Enhanced Distributed Coordination Function (EDCF);

FIG. 11 shows a table with exemplary values of the respective minimumoutput power and transmission bandwidth (BW) corresponding to differentchannel BW configurations for Long Term Evolution (LTE) signals, andalso shows an exemplary diagram plotting minimum output power over theapplicable frequency spectrum for certain Wi-Fi signals;

FIG. 12 shows a block diagram illustrating an exemplary method fordetecting LAA signals using band-pass filtering and power estimation,according to some embodiments;

FIG. 13 shows an exemplary block diagram illustrating Power SpectralDensity (PSD) estimation, according to some embodiments;

FIG. 14 shows a diagram of an exemplary radio frame, indicatingsubframes and time slots within the subframes to indicate when PrimarySynchronization Signal (PSS) and Secondary Synchronization Signal (SSS)are transmitted;

FIG. 15 shows a control diagram illustrating an exemplary system/methodfor a Wi-Fi controller to perform x-correlation between a receivedsignal and Zadoff-Chu sequences for detecting an LTE PSS, according tosome embodiments;

FIG. 16 shows a more detailed version of the signal diagrams forZadoff-Chu sequence 34 from FIG. 15;

FIG. 17 shows a block diagram illustrating interaction betweenarchitectural layers within a wireless communication device to mitigateLAA impact on Wi-Fi communications, according to some embodiments;

FIG. 18 shows a flow diagram of an exemplary method for mitigating LAAimpact on Wi-Fi communications in peer-to-peer mode of operation,according to some embodiments;

FIG. 19 shows a flow diagram of an exemplary method for mitigating LAAimpact on Wi-Fi communications in Access Point (AP) mode of operation,according to some embodiments; and

FIG. 20 shows a flow diagram of an exemplary method for mitigating LAAimpact on Wi-Fi communications in station mode of operation, accordingto some embodiments.

While features described herein are susceptible to various modificationsand alternative forms, specific embodiments thereof are shown by way ofexample in the drawings and are herein described in detail. It should beunderstood, however, that the drawings and detailed description theretoare not intended to be limiting to the particular form disclosed, but onthe contrary, the intention is to cover all modifications, equivalentsand alternatives falling within the spirit and scope of the subjectmatter as defined by the appended claims.

DETAILED DESCRIPTION OF THE EMBODIMENTS Acronyms

Various acronyms are used throughout the present application.Definitions of the most prominently used acronyms that may appearthroughout the present application are provided below:

-   AMR-WB: Adaptive Multi-Rate Wideband-   AP: Access Point-   APN: Access Point Name-   APR: Applications Processor-   BS: Base Station-   BSR: Buffer Size Report-   CMR: Change Mode Request-   DL: Downlink (from BS to UE)-   DYN: Dynamic-   EDCF: Enhanced Distributed Coordination Function-   FDD: Frequency Division Duplexing-   FO: First-Order state-   FT: Frame Type-   GPRS: General Packet Radio Service-   GSM: Global System for Mobile Communication-   GTP: GPRS Tunneling Protocol-   IR: Initialization and Refresh state-   LAN: Local Area Network-   LBT: Listen Before Talk-   LTE: Long Term Evolution-   PDCP: Packet Data Convergence Protocol-   PDN: Packet Data Network-   PDU: Protocol Data Unit-   PGW: PDN Gateway-   PSD: Power Spectral Density-   PSS: Primary Synchronization Signal-   PT: Payload Type-   RAT: Radio Access Technology-   RF: Radio Frequency-   ROHC: Robust Header Compression-   RTP: Real-time Transport Protocol-   RX: Reception/Receive-   SID: System Identification Number-   SGW: Serving Gateway-   SSS: Secondary Synchronization Signal-   TBS: Transport Block Size-   TDD: Time Division Duplexing-   TX: Transmission/Transmit-   UE: User Equipment-   UL: Uplink (from UE to BS)-   UMTS: Universal Mobile Telecommunication System-   Wi-Fi: Wireless Local Area Network (WLAN) RAT based on the Institute    of Electrical and Electronics Engineers' (IEEE) 802.11 standards-   WLAN: Wireless LAN

Terms

The following is a glossary of terms that may appear in the presentapplication:

Memory Medium—Any of various types of memory devices or storage devices.The term “memory medium” is intended to include an installation medium,e.g., a CD-ROM, floppy disks, or tape device; a computer system memoryor random access memory such as DRAM, DDR RAM, SRAM, EDO RAM, RambusRAM, etc.; a non-volatile memory such as a Flash, magnetic media, e.g.,a hard drive, or optical storage; registers, or other similar types ofmemory elements, etc. The memory medium may comprise other types ofmemory as well or combinations thereof. In addition, the memory mediummay be located in a first computer system in which the programs areexecuted, or may be located in a second different computer system whichconnects to the first computer system over a network, such as theInternet. In the latter instance, the second computer system may provideprogram instructions to the first computer system for execution. Theterm “memory medium” may include two or more memory mediums which mayreside in different locations, e.g., in different computer systems thatare connected over a network.

Carrier Medium—a memory medium as described above, as well as a physicaltransmission medium, such as a bus, network, and/or other physicaltransmission medium that conveys signals such as electrical,electromagnetic, or digital signals.

Computer System (or Computer)—any of various types of computing orprocessing systems, including a personal computer system (PC), mainframecomputer system, workstation, network appliance, Internet appliance,personal digital assistant (PDA), television system, grid computingsystem, or other device or combinations of devices. In general, the term“computer system” may be broadly defined to encompass any device (orcombination of devices) having at least one processor that executesinstructions from a memory medium.

User Equipment (UE) (or “UE Device”)—any of various types of computersystems devices which perform wireless communications. Also referred toas wireless communication devices, many of which may be mobile and/orportable. Examples of UE devices include mobile telephones or smartphones (e.g., iPhone™, Android™-based phones) and tablet computers suchas iPad™, Samsung Galaxy™, etc., gaming devices (e.g. Sony PlayStation™,Microsoft XBox™, etc.), portable gaming devices (e.g., Nintendo DS™,PlayStation Portable™, Gameboy Advance™, iPod™), laptops, wearabledevices (e.g. Apple Watch™, Google Glass™), PDAs, portable Internetdevices, music players, data storage devices, or other handheld devices,etc. Various other types of devices would fall into this category ifthey include Wi-Fi or both cellular and Wi-Fi communication capabilitiesand/or other wireless communication capabilities, for example overshort-range radio access technologies (SRATs) such as BLUETOOTH™, etc.In general, the term “UE” or “UE device” may be broadly defined toencompass any electronic, computing, and/or telecommunications device(or combination of devices) which is capable of wireless communicationand may also be portable/mobile.

Base Station (BS)—The term “Base Station” has the full breadth of itsordinary meaning, and at least includes a wireless communication stationinstalled at a fixed location and used to communicate as part of awireless telephone system or radio system.

Processing Element—refers to various elements or combinations ofelements that are capable of performing one or more functions in adevice, e.g. in a user equipment device or in a cellular network device,and/or cause the user equipment device or cellular network device toperform one or more functions. Processing elements may include, forexample: processors and associated memory, portions or circuits ofindividual processor cores, entire processor cores, processor arrays,circuits such as an ASIC (Application Specific Integrated Circuit),programmable hardware elements such as a field programmable gate array(FPGA), as well any of various combinations of the above.

Wireless Device (or wireless communication device)—any of various typesof computer systems devices which performs wireless communications usingWLAN communications, SRAT communications, Wi-Fi communications and thelike. As used herein, the term “wireless device” may refer to a UEdevice, as defined above, or to a stationary device, such as astationary wireless client or a wireless base station. For example awireless device may be any type of wireless station of an 802.11 system,such as an access point (AP) or a client station (UE), or any type ofwireless station of a cellular communication system communicatingaccording to a cellular radio access technology (e.g. LTE, CDMA, GSM),such as a base station or a cellular telephone, for example.

Wi-Fi—The term “Wi-Fi” has the full breadth of its ordinary meaning, andat least includes a wireless communication network or RAT that isserviced by wireless LAN (WLAN) access points and which providesconnectivity through these access points to the Internet. Most modernWi-Fi networks (or WLAN networks) are based on IEEE 802.11 standards andare marketed under the name “Wi-Fi”. A Wi-Fi (WLAN) network is differentfrom a cellular network.

Automatically—refers to an action or operation performed by a computersystem (e.g., software executed by the computer system) or device (e.g.,circuitry, programmable hardware elements, ASICs, etc.), without userinput directly specifying or performing the action or operation. Thusthe term “automatically” is in contrast to an operation being manuallyperformed or specified by the user, where the user provides input todirectly perform the operation. An automatic procedure may be initiatedby input provided by the user, but the subsequent actions that areperformed “automatically” are not specified by the user, i.e., are notperformed “manually”, where the user specifies each action to perform.For example, a user filling out an electronic form by selecting eachfield and providing input specifying information (e.g., by typinginformation, selecting check boxes, radio selections, etc.) is fillingout the form manually, even though the computer system must update theform in response to the user actions. The form may be automaticallyfilled out by the computer system where the computer system (e.g.,software executing on the computer system) analyzes the fields of theform and fills in the form without any user input specifying the answersto the fields. As indicated above, the user may invoke the automaticfilling of the form, but is not involved in the actual filling of theform (e.g., the user is not manually specifying answers to fields butrather they are being automatically completed). The presentspecification provides various examples of operations beingautomatically performed in response to actions the user has taken.

Station (STA)—The term “station” herein refers to any device that hasthe capability of communicating wirelessly, e.g. by using the 802.11protocol. A station may be a laptop, a desktop PC, PDA, access point orWi-Fi phone or any type of device similar to a UE. An STA may be fixed,mobile, portable or wearable. Generally in wireless networkingterminology, a station (STA) broadly encompasses any device withwireless communication capabilities, and the terms station (STA),wireless client (UE) and node (BS) are therefore often usedinterchangeably.

Configured to—Various components may be described as “configured to”perform a task or tasks. In such contexts, “configured to” is a broadrecitation generally meaning “having structure that” performs the taskor tasks during operation. As such, the component can be configured toperform the task even when the component is not currently performingthat task (e.g., a set of electrical conductors may be configured toelectrically connect a module to another module, even when the twomodules are not connected). In some contexts, “configured to” may be abroad recitation of structure generally meaning “having circuitry that”performs the task or tasks during operation. As such, the component canbe configured to perform the task even when the component is notcurrently on. In general, the circuitry that forms the structurecorresponding to “configured to” may include hardware circuits.

Various components may be described as performing a task or tasks, forconvenience in the description. Such descriptions should be interpretedas including the phrase “configured to.” Reciting a component that isconfigured to perform one or more tasks is expressly intended not toinvoke 35 U.S.C. § 112, paragraph six, interpretation for thatcomponent.

FIGS. 1 and 2—Exemplary Communication System

FIG. 1 illustrates an exemplary (and simplified) wireless communicationsystem, according to some embodiments. It is noted that the system ofFIG. 1 is merely one example of a possible system, and embodiments maybe implemented in any of various systems, as desired.

As shown, the exemplary wireless communication system includes a basestation 102 which communicates over a transmission medium with one ormore user devices 106-1 through 106-N. Each of the user devices may bereferred to herein as a “user equipment” (UE) or UE device. Thus, theuser devices 106 are referred to as UEs or UE devices. Various ones ofthe UE devices may operate according to a new category [definition] asdetailed herein.

The base station 102 may be a base transceiver station (BTS) or cellsite, and may include hardware that enables wireless communication withthe UEs 106A through 106N. The base station 102 may also be equipped tocommunicate with a network 100 (e.g., a core network of a cellularservice provider, a telecommunication network such as a public switchedtelephone network (PSTN), and/or the Internet, among variouspossibilities). Thus, the base station 102 may facilitate communicationbetween the user devices and/or between the user devices and the network100. The communication area (or coverage area) of the base station maybe referred to as a “cell.” It should also be noted that “cell” may alsorefer to a logical identity for a given coverage area at a givenfrequency. In general, any independent cellular wireless coverage areamay be referred to as a “cell”. In such cases a base station may besituated at particular confluences of three cells. The base station, inthis uniform topology, may serve three 120 degree beam width areasreferenced as cells. Also, in case of carrier aggregation, small cells,relays, etc. may each represent a cell. Thus, in carrier aggregation inparticular, there may be primary cells and secondary cells which mayservice at least partially overlapping coverage areas but on differentrespective frequencies. For example, a base station may serve any numberof cells, and cells served by a base station may or may not becollocated (e.g. remote radio heads). As also used herein, from theperspective of UEs, a base station may sometimes be considered asrepresenting the network insofar as uplink and downlink communicationsof the UE are concerned. Thus, a UE communicating with one or more basestations in the network may also be interpreted as the UE communicatingwith the network.

The base station 102 and the user devices may be configured tocommunicate over the transmission medium using any of various radioaccess technologies (RATs), also referred to as wireless communicationtechnologies, or telecommunication standards, such as GSM, UMTS (WCDMA),LTE, LTE-Advanced (LTE-A), LAA/LTE-U, 3GPP2 CDMA2000 (e.g., 1×RTT,1×EV-DO, HRPD, eHRPD), Wi-Fi, WiMAX etc. In some embodiments, the basestation 102 communicates with at least one UE using improved UL (Uplink)and DL (Downlink) decoupling, preferably through LTE or a similar RATstandard.

UE 106 may be capable of communicating using multiple wirelesscommunication standards. For example, a UE 106 might be configured tocommunicate using either or both of a 3GPP cellular communicationstandard (such as LTE) or a 3GPP2 cellular communication standard (suchas a cellular communication standard in the CDMA2000 family of cellularcommunication standards). Base station 102 and other similar basestations operating according to the same or a different cellularcommunication standard may thus be provided as one or more networks ofcells, which may provide continuous or nearly continuous overlappingservice to UE 106 and similar devices over a wide geographic area viaone or more cellular communication standards.

The UE 106 might also or alternatively be configured to communicateusing WLAN, BLUETOOTH™, one or more global navigational satellitesystems (GNSS, e.g., GPS or GLONASS), one and/or more mobile televisionbroadcasting standards (e.g., ATSC-M/H or DVB-H), etc. Othercombinations of wireless communication standards (including more thantwo wireless communication standards) are also possible.

FIG. 2 illustrates an exemplary user equipment 106 (e.g., one of thedevices 106-1 through 106-N) in communication with the base station 102,according to some embodiments. The UE 106 may be a device with wirelessnetwork connectivity such as a mobile phone, a hand-held device, acomputer or a tablet, or virtually any type of wireless device. The UE106 may include a processor that is configured to execute programinstructions stored in memory. The UE 106 may perform any of the methodembodiments described herein by executing such stored instructions.Alternatively, or in addition, the UE 106 may include a programmablehardware element such as an FPGA (field-programmable gate array) that isconfigured to perform any of the method embodiments described herein, orany portion of any of the method embodiments described herein. The UE106 may be configured to communicate using any of multiple wirelesscommunication protocols. For example, the UE 106 may be configured tocommunicate using two or more of CDMA2000, LTE, LTE-A, WLAN, or GNSS.Other combinations of wireless communication standards are alsopossible.

The UE 106 may include one or more antennas for communicating using oneor more wireless communication protocols according to one or more RATstandards. In some embodiments, the UE 106 may share one or more partsof a receive chain and/or transmit chain between multiple wirelesscommunication standards. The shared radio may include a single antenna,or may include multiple antennas (e.g., for MIMO) for performingwireless communications. Alternatively, the UE 106 may include separatetransmit and/or receive chains (e.g., including separate antennas andother radio components) for each wireless communication protocol withwhich it is configured to communicate. As another alternative, the UE106 may include one or more radios which are shared between multiplewireless communication protocols, and one or more radios which are usedexclusively by a single wireless communication protocol. For example,the UE 106 may include a shared radio for communicating using either ofLTE or CDMA2000 1×RTT, and separate radios for communicating using eachof Wi-Fi and BLUETOOTH™. Other configurations are also possible.

FIG. 3—Block Diagram of an Exemplary UE

FIG. 3 illustrates a block diagram of an exemplary UE 106, according tosome embodiments. As shown, the UE 106 may include a system on chip(SOC) 300, which may include portions for various purposes. For example,as shown, the SOC 300 may include processor(s) 302 which may executeprogram instructions for the UE 106 and display circuitry 304 which mayperform graphics processing and provide display signals to the display360. The processor(s) 302 may also be coupled to memory management unit(MMU) 340, which may be configured to receive addresses from theprocessor(s) 302 and translate those addresses to locations in memory(e.g., memory 306, read only memory (ROM) 350, NAND flash memory 310)and/or to other circuits or devices, such as the display circuitry 304,radio 330, connector I/F 320, and/or display 360. The MMU 340 may beconfigured to perform memory protection and page table translation orset up. In some embodiments, the MMU 340 may be included as a portion ofthe processor(s) 302.

As shown, the SOC 300 may be coupled to various other circuits of the UE106. For example, the UE 106 may include various types of memory (e.g.,including NAND flash 310), a connector interface 320 (e.g., for couplingto the computer system), the display 360, and wireless communicationcircuitry (e.g., for LTE, LTE-A, CDMA2000, BLUETOOTH™, Wi-Fi, GPS,etc.). The UE device 106 may include at least one antenna (e.g. 335 a),and possibly multiple antennas (e.g. illustrated by antennas 335 a and335 b), for performing wireless communication with base stations and/orother devices. Antennas 335 a and 335 b are shown by way of example, andUE device 106 may include fewer or more antennas. Overall, the one ormore antennas are collectively referred to as antenna(s) 335. Forexample, the UE device 106 may use antenna(s) 335 to perform thewireless communication with the aid of radio circuitry 330. As notedabove, the UE may be configured to communicate wirelessly using multiplewireless communication standards in some embodiments.

As described further subsequently herein, the UE 106 (and/or basestation 102) may include hardware and software components forimplementing methods for at least UE 106 to detect LAA/LTE-U signals andmitigate the impact of those signals on communications taking placewithin the same band but according to different RATs, for exampleaccording to Wi-Fi. Thus, in some embodiments, UE 106 may detectLAA/LTE-U signals and mitigate the impact of those signals on Wi-Ficommunications performed by UE 106. The processor(s) 302 of the UEdevice 106 may be configured to implement part or all of the methodsdescribed herein, e.g., by executing program instructions stored on amemory medium (e.g., a non-transitory computer-readable memory medium).In other embodiments, processor(s) 302 may be configured as aprogrammable hardware element, such as an FPGA (Field Programmable GateArray), or as an ASIC (Application Specific Integrated Circuit).Furthermore, processor(s) 302 may be coupled to and/or may interoperatewith other components as shown in FIG. 3, to implement communications byUE 106 that incorporate mitigating the effect of LAA/LTE-Ucommunications on Wi-Fi communications by UE 106 according to variousembodiments disclosed herein. Specifically, processor(s) 302 may becoupled to and/or may interoperate with other components as shown inFIG. 3 to facilitate UE 106 communicating in a manner that seeks tooptimize Wi-Fi communications of UE 106 through the detection ofLAA/LTE-U signals. Processor(s) 302 may also implement various otherapplications and/or end-user applications running on UE 106.

In some embodiments, radio 330 may include separate controllersdedicated to controlling communications for various respective RATstandards. For example, as shown in FIG. 3, radio 330 may include aWi-Fi controller 351, a cellular controller (e.g. LTE controller) 352,and BLUETOOTH′ controller 354, and in at least some embodiments, one ormore or all of these controllers may be implemented as respectiveintegrated circuits (ICs or chips, for short) in communication with eachother and with SOC 300 (and more specifically with processor(s) 302).For example, Wi-Fi controller 351 may communicate with cellularcontroller 352 over a cell-ISM link or WCI interface, and/or BLUETOOTH′controller 354 may communicate with cellular controller 352 over acell-ISM link, etc. While three separate controllers are illustratedwithin radio 330, other embodiments have fewer or more similarcontrollers for various different RATs that may be implemented in UEdevice 106.

FIG. 4—Block Diagram of an Exemplary Base Station

FIG. 4 illustrates a block diagram of an exemplary base station 102,according to some embodiments. It is noted that the base station of FIG.4 is merely one example of a possible base station. As shown, the basestation 102 may include processor(s) 404 which may execute programinstructions for the base station 102. The processor(s) 404 may also becoupled to memory management unit (MMU) 440, which may be configured toreceive addresses from the processor(s) 404 and translate thoseaddresses to locations in memory (e.g., memory 460 and read only memory(ROM) 450) or to other circuits or devices.

The base station 102 may include at least one network port 470. Thenetwork port 470 may be configured to couple to a telephone network andprovide a plurality of devices, such as UE devices 106, access to thetelephone network as described above in FIGS. 1 and 2. The network port470 (or an additional network port) may also or alternatively beconfigured to couple to a cellular network, e.g., a core network of acellular service provider. The core network may provide mobility relatedservices and/or other services to a plurality of devices, such as UEdevices 106. In some cases, the network port 470 may couple to atelephone network via the core network, and/or the core network mayprovide a telephone network (e.g., among other UE devices serviced bythe cellular service provider).

The base station 102 may include at least one antenna 434, and possiblymultiple antennas. The at least one antenna 434 may be configured tooperate as a wireless transceiver and may be further configured tocommunicate with UE devices 106 via radio 430. The antenna 434communicates with the radio 430 via communication chain 432.Communication chain 432 may be a receive chain, a transmit chain orboth. The radio 430 may be designed to communicate via various wirelesstelecommunication standards, including, but not limited to, LTE, LTE-AWCDMA, CDMA2000, etc. The processor(s) 404 of the base station 102 maybe configured to implement part or all of the methods described herein,e.g., by executing program instructions stored on a memory medium (e.g.,a non-transitory computer-readable memory medium), for base station 102to communicate with a UE device capable of detecting LAA/LTE-U signalsand mitigating the effects of those signals on Wi-Fi communicationsperformed by the UE device. Alternatively, the processor(s) 404 may beconfigured as a programmable hardware element, such as an FPGA (FieldProgrammable Gate Array), or as an ASIC (Application Specific IntegratedCircuit), or a combination thereof. In the case of certain RATs, forexample Wi-Fi, base station 102 may be designed as an access point (AP),in which case network port 470 may be implemented to provide access to awide area network and/or local area network (s), e.g. it may include atleast one Ethernet port, and radio 430 may be designed to communicateaccording to the Wi-Fi standard. Base station 102 may operate accordingto the various methods as disclosed herein for communicating with mobiledevices capable of mitigating the presence and effects of LAA/LTE-Usignals on Wi-Fi communications (also) performed by the mobile devices.

FIG. 5—Exemplary Communication System

FIG. 5 illustrates an exemplary wireless communication system 500 inaccordance with some embodiments. System 500 is a system in which an LTEaccess network and a Wi-Fi radio access network are implemented. Thesystem 500 may include UE 106 and LTE network 504 and Wi-Fi network 506.

LTE access network 504 is representative of some embodiments of a firstRAT access and Wi-Fi access network 506 is representative of someembodiments of a second RAT access. LTE access network 504 may beinterfaced with a broader cellular network (e.g. LTE network) and Wi-Fiaccess network 506 may be interfaced with the Internet 514. Moreparticularly, LTE access network 504 may be interfaced with a servingbase station (BS) 508, which may in turn provide access to broadercellular network 516. The Wi-Fi access network 506 may be interfacedwith an access point (AP) 510, which may in turn provide access to theInternet 514. UE 106 may accordingly access Internet 514 via AP 510 andmay access cellular network 516 via LTE access network 504. In someembodiments, not shown, UE 106 may also access Internet 514 via LTEaccess network 504. More specifically, LTE access network 504 may beinterfaced with a serving gateway, which may in turn be interfaced witha packet data network (PDN) gateway. The PDN gateway may, in turn, beinterfaced with Internet 514. UE 106 may accordingly access Internet 514via either or both of LTE access network 504 and Wi-Fi access network506.

FIG. 6—Exemplary Communication System with Multiple Wi-Fi Devices

FIG. 6 shows an exemplary communication system in which multipledifferent devices may communicate with each other over a specific band,such as 2.4 GHz and/or 5 GHz frequency bands using Wi-Fi RAT. 5 GHzWi-Fi (IEEE 802.11 ac/n) capable devices have become quite common,operating in both peer-to-peer mode and/or station mode, as shown inFIG. 6. Data communications over a specific frequency band, e.g. overthe 5 GHz band may include Voice, Video, real time and best effort typeof traffic. Illustrated devices include cameras (111), tablets (113),media servers/mini-servers (115), portable computers (105, 117), accessports/routers (103), game controllers (119), mobile devices such assmart phones (107), and smart monitors (121) or monitors with wirelessaccess interface (121 together with 123). As shown in FIG. 6, many ofthe devices may communicate over the 5 GHz band, using Wi-Ficommunication technology. In some cases the Wi-Fi communicationsconducted by the devices may be affected by LAA/LTE-U communicationsalso taking place over the 5 GHz band.

Presence of LAA/LTE-U Signals

In LTE, carrier aggregation (CA) refers to the process of aggregatingtwo or more component carriers (CCs) in order to support widertransmission bandwidths, e.g. bandwidths of up to 100 MHz. A UE maysimultaneously receive or transmit on one or multiple CCs depending onthe UE's capabilities. When CA is configured, the UE may maintain oneRRC connection with the network. The serving cell managing the UE's RRCconnection is referred to as the Primary Cell (PCell), and SecondaryCells (SCells) together with the PCell may form a set of serving cells.In CA, a UE may be scheduled via PDCCH over multiple serving cellssimultaneously. Cross-carrier scheduling with the Carrier IndicatorField (CIF) allows the PDCCH of a serving cell to schedule resources onanother serving cell. That is, a UE receiving a downlink assignment onone CC may receive associated data on another CC.

LAA is a sub-category of LTE inter-band carrier aggregation, where oneof the secondary carriers is operating in an unlicensed (e.g. 5 GHz)band, a band over which communications according to another RAT, such asWi-Fi may also be taking place. Resources in an LAA carrier arescheduled in the same manner as in legacy CA. That is, carrierscheduling and/or cross layer scheduling for LAA carriers are the sameas for other CA carriers (PDCCH or ePDCCH). An LAA Scell may operate ina frame structure 3 composed of 20 slots, and may be accessed followinga successful listen-before-talk (LBT) procedure. FIG. 7 shows an exampleof typical LAA control and data scheduling, providing a respectiveexample for same carrier scheduling (201) and a respective example forcross carrier scheduling (251), assuming a successfully completed LBTprocedure in the previous subframe. If a start position of the RadioResource Control (RRC) subframe indicates ‘s07’, and no DCI is receivedin slot1, the UE may read the PDCC/ePDCCH of slot2 to check downlinkdata availability.

FIG. 8 shows an exemplary flowchart for LBT procedures. FIG. 9 shows atable with exemplary values for various parameters for LAA LBT. FIG. 10shows a table with exemplary values for the same parameters for Wi-FiEDCF (Enhanced Distributed Coordination Function) in the 5 GHz band. Aspreviously mentioned, the presence of LAA communications (in the 5 GHzband) may lead to performance degradation of signal throughput as wellas decreased performance of real-time VoIP and/or video transmissions ofWi-Fi communications (in the 5 GHz band).

Detection of LAA/LTE-U Signals

In some embodiments, wireless communication devices operating accordingto a first RAT in a specified frequency band may be configured to detectwireless signals from communications performed according to a second RATin the same frequency band while the wireless communication devices arecommunicating according to the first RAT in the specified frequencyband. For example, in some embodiments, wireless communication devices(e.g. Wi-Fi stations and access points) that perform Wi-Ficommunications in the 5 GHz band in peer-to-peer mode may detect LAAsignals. In one set of embodiments, the signal detection may beperformed through PSD (power spectral density) bandwidth differentiationand/or through blind PSS/SSS (Primary Synchronization Signal/SecondarySynchronization Signal) decoding. The detection may be performeddynamically during normal Wi-Fi RX Operations or during a DynamicFrequency Selection Procedure (radar scan procedure). In another set ofembodiments, peer-to-peer wireless links may be used for crowdsourcingthe location of LAA small cells and LAA operating frequencies. That is,through real time information/data obtained via the peer-to-peerwireless links from different respective locations, the location of LAAsmall cells and LAA operating frequencies may be determined.Furthermore, LTE modem signaling may be used to acquire informationabout LAA channels, which may be applicable in case of wirelesscommunication devices performing both cellular and Wi-Fi communications(e.g. smart phones, tablets, etc.)

Based on the LAA signal detection, the impact of the LAA signals on theWi-Fi traffic (whether operating in station mode or peer-to-peer mode)may be mitigated. Characteristics and/or parameters associated withWi-Fi communications that may be adjusted include Wi-Fi Rate Adaptation(AMPDU), Wi-Fi Channel/Band Selection, Wi-Fi Voice/Video traffic taggingWMM (Wi-Fi Multimedia), Wi-Fi Gaming/control traffic WWM, and/or datatraffic just to name a few.

LTE Signals and Wi-Fi Signals

By way of example, a 20 MHz LTE signal may effectively occupy a transmitBW of 18 MHz. In such a case the signal may occupy 1200 subcarriers (inother words, the number of subcarriers occupied by the signal is 1200),where each subcarrier is 15 KHz wide (that is, each subcarrier has a BWof 15 KHz). Table 650 in FIG. 11 provides an exemplary summary of therespective minimum output power (in dBm) and transmission BWcorresponding to different channel BW configurations for LTE signals. Incontrast, a 20 MHz Wi-Fi signal may effectively occupy a BW of 16.25MHz, with 52 subcarriers of 312.5 KHz each, as illustrated in diagram600 of FIG. 11, plotting the minimum output power over the applicablefrequency spectrum. Diagram 600 also illustrates the corresponding802.11 a/g transmit spectrum mask 602.

LAA Signal Detection Using Band-pass Filtering and Power Estimation

FIG. 12 shows a block diagram illustrating an exemplary method fordetecting LAA signals using band-pass filtering and power estimation inview of the different characteristics/parameters pertaining to LTEsignals and Wi-Fi signals in the same frequency band as discussed above.As shown in FIG. 12, a digital estimation of the power of the basebandsignal may be performed (at 704 and 710) after filtering the incomingdigital baseband signal through two different complex bandpass filters(702 and 708) having different bandwidths. That is, the received digitalbaseband signal (e.g. quadrature baseband signals I and Q) is filteredthrough a first bandpass filter 702 having a BW of 16.25 MHz (associatedwith Wi-Fi signals present), and is also filtered through a secondbandpass filter 708 having a BW of 18/20 MHz (associated with LTEsignals and Wi-Fi signals both present). Thus, the filtered signal inthe 16.25 MHz bandwidth is used for estimating the power in the Wi-Fichannel (704), and the filtered signal in the 18 MHz (or 20 MHz)bandwidth is used for estimating the power in the LTE channel (710) inview of the power estimate obtained for the Wi-Fi channel. Thus, it ispossible to detect an LTE signal based on the power computation obtainedbased on the filtered signal from filter 702 by comparing the two powerestimates (from 704 and 710), for example by obtaining a ratio of linearvalues corresponding to the power estimates or a difference of dB valuescorresponding to the power estimates. The results from these powerestimations may then be used in/provided to an LAA signal detectionalgorithm 706.

LAA Power Spectral Density (PSD) Estimation

In one set of embodiments, LAA Signal Detection may be performed in aWi-Fi Receiver through determining/estimating the Power Spectral Density(PSD) of an LAA signal. A Wi-Fi receiver may scan the full unlicensedband for an LTE signal, and/or it may scan for a particular channel inthe frequency domain. In case of a full band scan, a PSD estimate forthe unlicensed band may be obtained, and an algorithm may be used fordetecting an LTE signal based on the PSD estimate. The algorithm may bedevised to correlate the captured/estimated PSD with an LTE OFDM signal.In the case of the presence of an LTE signal (per the PSD), thecorrelation will be of a shape of a rectangle. In other words, if thecorrelation of the PSD has the shape of rectangle over an 18 MHzbandwidth, it indicates the presence of an LTE signal. The algorithm mayalso be devised to incorporate conditions on the flatness of thespectrum within the transmit band and spectrum drop at the edge[s] ofthe 18 MHz transmit band. Accounting for these conditions may helpimprove the detectability since LTE and Wi-Fi are represented bydifferent transmit masks due to different requirements and differentshaping filters used in RF. In some embodiments, PSD estimation may beperformed through a periodogram, which is the Fourier transform of theautocorrelation of the signal. The basic flow of such estimation isillustrated by the exemplary block diagram shown in FIG. 13. Thehardware complexity of such a solution may be rather simple, and may notrequire any RF hardware modifications with respect to already existingRF hardware. For example, I/Q samples at the output of the ADC (750) inWi-Fi may be used to build a periodogram (through 754 and 756)—e.g. byperforming DSP operations that may already be available in the Wi-Fitransceiver—without requiring any specific LTE receiver implementations.The PSD estimation may be obtained based on the periodogram (via 758).

LAA Synchronization Signal Detection

In one set of embodiments, LAA Signal Detection may be performed in aWi-Fi Receiver through the detection of LAA synchronization signaldetection, e.g. through detecting a primary synchronization signal (PSS)and/or secondary synchronization signal (SSS). Both the FDD (FrequencyDivision Duplex) and TDD (Time Division Duplex) versions of LAAbroadcast synchronization signals in the downlink direction include PSSand SSS. The PSS and SSS are broadcast during DRS (demodulationreference signal) occasions in LAA (the DRS occasion is set by the eNB,i.e. by the base station). The primary synchronization signal (PSS) istypically based on a predetermined Zadoff-Chu sequence giving the cellidentity within the group. Three possible Zadoff-Chu sequences (25, 29,and 34) may be used. FIG. 14 shows a diagram of an exemplary radioframe, indicating subframes and time slots within the subframes toindicate when PSS and SSS are transmitted.

In order to detect LAA, the wireless communication device (e.g. via theWi-Fi controller 351 within UE 106 shown in FIG. 3) may receive anysignal in its operating frequency. However, instead of rejecting asignal without Wi-Fi Preamble —that is, without rejecting a signalreceived within the frequency band but not associated with the RAT thedevice is expecting the signal to be associated with—the receiver maylook for the LAA PSS. For example, the Wi-Fi controller may usex-correlation in the time domain between the received signal x(m) andthe three possible Zadoff-Chu sequences Z(m). As mentioned above, insome embodiments, three possible Zadoff-Chu sequences (25, 29, and 34)may be used. The detected PSS signal may then be obtained based on thefollowing equation:

${D(n)} = {\sum\limits_{m = 1}^{N}\;{{x\left( {m + n} \right)}{Z^{*}(m)}}}$

In the equation above, “n” refers to the length of the sequence. FIG. 15shows a control diagram 900 illustrating an exemplary system/method fora Wi-Fi controller to perform x-correlation between a received signalx(m) and the Zadoff-Chu sequences for detecting an LTE PSS. As shown inFIG. 15, the signal from a front-end RF circuit 902 may be provided toan analog to digital converter (ADC) 904, and digital signal processing(e.g. sample rate converter filtering) may be performed on the digitizedsignal (at 906). The resulting quadrature signals may be provided tomixer 908 to correlate with the given Zadoff-Chu sequence (910),generating the samples in 912 which are then used for the threshold vs.signal to noise (SNR) ratio comparison in 914. FIG. 15 also includessignal diagrams 940 plotting the respective amplitudes versus time ofthe real part and imaginary part of Zadoff-Chu sequence 34. Signaldiagram 950 plots the amplitude versus time of the detected signaloutput from 912. FIG. 16 shows a more detailed version of the respectivesignal diagrams 940 (Real part and Imaginary part) for Zadoff-Chusequence 34.

LAA/LTE-U Small Cells Crowdsourcing

In some embodiments, peer-to-peer connections may be used for LAA/LTE-Usmall cells crowdsourcing. No hardware or system changes in the Wi-Ficontroller/hardware may be required to detect the presence of LAAcommunications. In this case, two semi-static approaches may be used to“detect” LAA presence in the channel.

A first approach may be based on crowd sourcing and peer-to-peerconnectivity. The Wi-Fi controller may be updated, e.g. by feedback,from newer UEs, with the detected LAA channels and the locations. Wi-Fidevices may use Wi-Fi positioning to estimate their respective positionsand correlate the (respective) position with peer-to-peer data in orderto retrieve operating LAA cells and their operating channels.

A second approach may be applicable to devices that are also cellularcapable in addition to being Wi-Fi capable. If the LTE RRC signalingindicates that CA (carrier aggregation) in the 5 GHz band is supportedin the eNB, and the NW (e.g. eNB) provides carrier combinations within 5GHz, then the cellular controller (e.g. controller 352 shown in FIG. 3for UE 106) may share this information with the Wi-Fi controller and/orWi-Fi driver in the UE. The Wi-Fi driver (and/or Wi-Fi controller) mayuse this information to perform Wi-Fi performance mitigation in thefrequencies/channels where LAA/LTE-U cells are known to operate.

Wi-Fi/AP Extension Support for LAA Impact Mitigation

FIG. 17 shows a block diagram illustrating interaction betweenarchitectural layers within a wireless communication device to mitigateLAA impact on Wi-Fi communications. In some embodiments, WLAN/Wi-Fi(peer-to-peer) driver 1010 may be configured to perform Wi-Fi/LAA impactmitigation. As shown in FIG. 17, a WLAN/Wi-Fi peer-to-peermanager/driver 1010 may communicate across an IPC (Inter-ProcessCommunication) layer 1012 with the MAC layer 1014 to mitigate LAAeffects on Wi-Fi communications. Detection of an LAA signal/waveform atthe physical layer (PHY) 1016 may be indicated to the WLAN/Wi-Fipeer-to-peer driver/manager 1010, (which may be WMM enabled) andpossibly change the Wi-Fi communication channel in response to the LAAsignal/waveform detection. Possible types of Wi-Fi communications thatmay be taking place include data transmissions associated withapplication(s) 1002, VoIP 1004 and/or video 1006.

FIG. 18—Flow Diagram of Exemplary Method for LAA Impact Mitigation inPeer-to-peer Mode of Operation

FIG. 18 shows a flow diagram 1100 of an exemplary method for mitigatingLAA impact on Wi-Fi communications in peer-to-peer mode of operation,according to some embodiments. As shown in FIG. 18, a Wi-Fi controllerin a wireless communication device (e.g. Wi-Fi controller 351 shown inFIG. 3 for UE 106) or any device communicating over Wi-Fi in apeer-to-peer mode may detect the presence of cellular communications inthe operating channel within frequency band in which the Wi-Ficommunications are taking place, e.g. in the 5 GHz band (1102). Morespecifically, the Wi-Fi controller may detect the presence of LAA/LTE-Usignals/communications in the operating channel within the 5 GHz bandwhile performing Wi-Fi communications over the operating channel. TheWi-Fi controller may inform the other peer of the peer-to-peerconnection that LAA/LTE-U communications are present in the operatingchannel (1104), and may perform various tasks to determine a mostappropriate course of action to mitigate the effects of the LAA/LTE-Ucommunications on the peer-to-peer Wi-Fi communications conducted by thedevice (which includes the Wi-Fi controller) with the other peer. Thetasks may include identifying the traffic type (at 1106, 1120, and1122), various supported modes of communication (1108), and varioussupported protocol data units (1124). Based on the identifications,various characteristics and/or parameters of the Wi-Fi communicationsmany be adjusted. Such adjustments may include the adjustments describedin 1126, 1114 (in response to an affirmative indication from 1108), 1116(in response to an affirmative indication from 1110), and 1118 (inresponse to an affirmative indication from 1112). The adjustment[s] mayinclude switching to an operating channel of another frequency band inorder to continue the Wi-Fi communications (1112, 1118).

It should be noted (with reference to at least FIGS. 18-20) that AIFSNrefers to Arbitration Inter-Frame Spacing Number and CWmax refers to themaximum size of the Contention Window. AISF and CW are used in Wi-Ficollision avoidance. Packet collisions in Wi-Fi may be avoided/minimizedthrough various Wi-Fi collision avoidance mechanisms which includeinter-frame spacing for different high-level frame types (for instance,control versus data frames), and a contention window to introducerandomness into the distributed medium contention logic of radiotransmitters since there is no central source of coordination betweenWi-Fi stations.

FIG. 19—Flow Diagram of Exemplary Method for LAA Impact Mitigation in APMode of Operation

FIG. 19 shows a flow diagram 1200 of an exemplary method for mitigatingLAA impact on Wi-Fi communications in AP mode of operation, according tosome embodiments. As shown in FIG. 19, a Wi-Fi access point (AP) devicecommunicating over Wi-Fi may detect the presence of cellularcommunications in the peer-to-peer operating channel within frequencyband in which the Wi-Fi communications are taking place, e.g. in the 5GHz band (1202). More specifically, the Wi-Fi AP may detect the presenceof LAA/LTE-U signals/communications in the operating channel within the5 GHz band while performing Wi-Fi communications over the operatingchannel. The Wi-Fi AP may perform various tasks to determine a mostappropriate course of action to mitigate the effects of the LAA/LTE-Ucommunications on the Wi-Fi communications conducted by the Wi-Fi AP(which may include a Wi-Fi controller performing these tasks). The tasksmay include identifying the traffic type (1204, 1218), various supportedmodes of communication (1206), and various supported protocol data units(1220). Based on the identifications, various characteristics and/orparameters of the Wi-Fi communications many be adjusted. Suchadjustments may include the adjustments described in 1222, 1212 (inresponse to an affirmative indication from 1206), 1214 (in response toand affirmative indication from 1208), and 1216 (in response to anaffirmative indication from 1210). The adjustment[s] may includeswitching to an operating channel of another frequency band in order tocontinue the Wi-Fi communications (1210, 1216).

FIG. 20—Flow Diagram of Exemplary Method for LAA Impact Mitigation inStation Mode of Operation

FIG. 20 shows a flow diagram 1300 of an exemplary method for mitigatingLAA impact on Wi-Fi communications in station mode of operation,according to some embodiments. As shown in FIG. 18, a Wi-Fi stationcommunicating over Wi-Fi with another peer may detect the presence ofcellular communications in the operating channel within frequency bandin which the Wi-Fi communications are taking place, e.g. in the 5 GHzband (1302). More specifically, the Wi-Fi station may detect thepresence of LAA/LTE-U signals/communications in the operating channelwithin the 5 GHz band while performing Wi-Fi communications over theoperating channel. The Wi-Fi AP station may perform various tasks todetermine a most appropriate course of action to mitigate the effects ofthe LAA/LTE-U communications on the Wi-Fi communications conducted bythe Wi-Fi station (which may include a Wi-Fi controller performing thesetasks). The tasks may include identifying the traffic type (1304, 1318),various supported modes of communication (1306), and various supportedprotocol data units (1320). Based on the identifications, variouscharacteristics and/or parameters of the Wi-Fi communications many beadjusted. Such adjustments may include the adjustments described in1322, 1312 (in response to an affirmative indication from 1306), 1314(in response to and affirmative indication from 1308), and 1316 (inresponse to an affirmative indication from 1310). The adjustment[s] mayinclude switching to an operating channel of another frequency band inorder to continue the Wi-Fi communications (1310, 1316).

Embodiments of the present invention may be realized in any of variousforms. For example, in some embodiments, the present invention may berealized as a computer-implemented method, a computer-readable memorymedium, or a computer system. In other embodiments, the presentinvention may be realized using one or more custom-designed hardwaredevices such as ASICs. In other embodiments, the present invention maybe realized using one or more programmable hardware elements such asFPGAs.

In some embodiments, a non-transitory computer-readable memory medium(e.g., a non-transitory memory element) may be configured so that itstores program instructions and/or data, where the program instructions,if executed by a computer system, cause the computer system to perform amethod, e.g., any of a method embodiments described herein, or, anycombination of the method embodiments described herein, or, any subsetof any of the method embodiments described herein, or, any combinationof such subsets.

In some embodiments, a device (e.g., a UE) may be configured to includea processor (or a set of processors) and a memory medium (or memoryelement), where the memory medium stores program instructions, where theprocessor is configured to read and execute the program instructionsfrom the memory medium, where the program instructions are executable toimplement any of the various method embodiments described herein (or,any combination of the method embodiments described herein, or, anysubset of any of the method embodiments described herein, or, anycombination of such subsets). The device may be realized in any ofvarious forms.

Although the embodiments above have been described in considerabledetail, numerous variations and modifications will become apparent tothose skilled in the art once the above disclosure is fully appreciated.It is intended that the following claims be interpreted to embrace allsuch variations and modifications.

The invention claimed is:
 1. An apparatus comprising: a memory elementstoring information; and a processing element configured to use at leasta portion of the information to cause a user equipment device (UE) to:conduct first wireless communications in a first frequency bandaccording to a first radio access technology (RAT), wherein the firstwireless communications comprise Wi-Fi communications; receiveinformation from one or more other UEs during the first communications,wherein the information is associated with respective wirelesscommunications conducted according to a second RAT by the one or moreother UEs; receive a signal in the first frequency band as part of thefirst communications, determine that the signal lacks an expectedpreamble associated with the first RAT, and detect that the signal is asynchronization signal associated with the second RAT partially inresponse to determining that the signal lacks the expected preamble;determine, based at least on the received information and the detectedsynchronization signal, that there is a presence of second wirelesscommunications conducted in the first frequency band according to thesecond RAT while the UE is conducting the first wireless communications,wherein the second wireless communications comprise cellular radiocommunications; and adjust the first wireless communications at least inresponse to and based on the detected second wireless communications. 2.The apparatus of claim 1, wherein the first frequency band is anunlicensed frequency band for the second wireless communications.
 3. Theapparatus of claim 1, wherein the UE is operating as one of: apeer-to-peer device; an access point; or a station.
 4. The apparatus ofclaim 1, wherein the processing element is configured to further causethe UE to detect an interfering second-RAT signal, wherein to detect theinterfering second-RAT signal, the processing element is configured tocause the UE to: bandpass filter, according to a first bandwidth, asignal received during the first wireless communications to produce afirst filtered signal; bandpass filter, according to a second bandwidth,the received signal to produce a second filtered signal; and determine apresence of the interfering second-RAT signal based on the firstfiltered signal and the second filtered signal.
 5. The apparatus ofclaim 1, wherein the processing element is configured to further causethe UE to detect interfering second-RAT signals by performing one ormore of the following: scanning the entire first frequency band;scanning, in the frequency domain, a particular channel of the firstfrequency band; or passively receiving signals when operating in aspecific channel of the first frequency band.
 6. The apparatus of claim5, wherein when scanning the entire first frequency band, the processingelement is configured to cause the UE to obtain a power spectral density(PSD) for the first frequency band.
 7. The apparatus of claim 6, whereinthe processing element is configured to further cause the UE to: performa correlation of the obtained PSD with a specific second-RAT signal; anddetect an interfering second-RAT signal of the interfering second-RATsignals based on the correlation.
 8. The apparatus of claim 6, whereinthe processing element is configured to further cause the UE to obtainthe PSD by performing a Fourier transform of an autocorrelation of asignal received during the first wireless communications.
 9. Theapparatus of claim 1, wherein the processing element is configured tocause the UE to detect that the signal is a synchronization signalassociated with the second RAT by using time domain x-correlationbetween the signal and one or more possible complex-valued mathematicalsequences.
 10. The apparatus of claim 1, wherein the UE is preconfiguredwith a list of known frequencies and/or known channels over which thesecond wireless communications are conducted.
 11. A user equipmentdevice (UE) comprising: first radio circuitry configured to facilitatewireless communications of the UE according to a first radio accesstechnology (RAT); second radio circuitry configured to facilitatewireless communications of the UE according to a second RAT; and aprocessing element configured to interoperate with the first radiocircuitry and the second radio circuitry to cause the UE to: conductfirst wireless communications in a first frequency band according to thefirst RAT; receive information from one or more other UEs during thefirst communications, wherein the information is associated withrespective wireless communications conducted according to a second RATby the one or more other UEs; receive a signal in the first frequencyband as part of the first communications, determine that the signallacks an expected preamble associated with the first RAT, and detectthat the signal is a synchronization signal associated with the secondRAT partially in response to determining that the signal lacks theexpected preamble; determine, based at least on the received informationand the detected synchronization signal, that there is a presence ofsecond wireless communications conducted in the first frequency bandaccording to the second RAT while the UE is conducting the firstwireless communications; and adjust the first wireless communications atleast in response to and based on the determined presence of the secondwireless communications.
 12. The UE of claim 11, wherein the processingelement is configured to interoperate with the first radio circuitry andthe second radio circuitry to further cause the UE to detect aninterfering second-RAT signal, wherein to detect the interferingsecond-RAT signal, the processing element is configured to interoperatewith the first radio circuitry and the second radio circuitry to causethe UE to: bandpass filter, according to a first bandwidth, a signalreceived during the first wireless communications to produce a firstfiltered signal; bandpass filter, according to a second bandwidth, thereceived signal to produce a second filtered signal; and determine apresence of the interfering second-RAT signal based on the firstfiltered signal and the second filtered signal.
 13. The UE of claim 11,wherein the processing element is configured to interoperate with thefirst radio circuitry and the second radio circuitry to further causethe wireless communication device to detect interfering second-RATsignals by performing one or more of the following: scanning the entirefirst frequency band; scanning, in the frequency domain, a particularchannel of the first frequency band; or passively receiving signals whenoperating in a specific channel of the first frequency band.
 14. The UEof claim 13, wherein the processing element is configured tointeroperate with the first radio circuitry and the second radiocircuitry to further cause the wireless communication device to: whenscanning the entire first frequency band, obtain a power spectraldensity (PSD) for the first frequency band; perform a correlation of theobtained PSD with a specific second-RAT signal; and detect aninterfering second-RAT signal of the interfering second-RAT signalsbased on the correlation.
 15. The UE of claim 11, wherein the processingelement is configured to interoperate with the first radio circuitry andthe second radio circuitry to further cause the UE to detect that thesignal is a synchronization signal associated with the second RAT byusing time domain x-correlation between the signal and one or morepossible complex-valued mathematical sequences.
 16. A non-transitorymemory element storing instructions executable by a processing elementto cause a user equipment device (UE) to: conduct first wirelesscommunications in a first frequency band according to a first radioaccess technology (RAT); receive information from one or more other UEsduring the first communications, wherein the information is associatedwith respective wireless communications conducted according to a secondRAT by the one or more other UEs; receive a signal in the firstfrequency band as part of the first communications, determine that thesignal lacks an expected preamble associated with the first RAT, anddetect that the signal is a synchronization signal associated with thesecond RAT partially in response to determining that the signal lacksthe expected preamble; determine, based at least on the receivedinformation and the detected synchronization signal, that there is apresence of second wireless communications conducted in the firstfrequency band according to the second RAT while the UE is conductingthe first wireless communications; and adjust the first wirelesscommunications at least in response to and based on the determinedpresence of the second wireless communications.
 17. The non-transitorymemory element of claim 16, wherein the instructions are executable bythe processing element to further cause the UE to detect an interferingsecond-RAT signal, wherein to detect the interfering second-RAT signal,the instructions are executable by the processing element to cause theUE to: produce a first filtered signal by bandpass filtering, accordingto a first bandwidth, a received signal during the first wirelesscommunications; produce a second filtered signal by bandpass filtering,according to a second bandwidth, the received signal; and determine apresence of the interfering second-RAT signal based on the firstfiltered signal and the second filtered signal.
 18. The non-transitorymemory element of claim 16, wherein the instructions are executable bythe processing element to further cause the UE to: to detect interferingsecond-RAT signals by performing one or more of the following: scanningthe entire first frequency band; scanning, in the frequency domain, aparticular channel of the first frequency band; or passively receivingsignals when operating in a specific channel of the first frequencyband.
 19. The non-transitory memory element of claim 18, wherein theinstructions are executable by the processing element to further causethe UE to: when scanning the entire first frequency band, obtain a powerspectral density (PSD) for the first frequency band; perform acorrelation of the obtained PSD with a specific second-RAT signal; anddetect an interfering second-RAT signal of the interfering second-RATsignals based on the correlation.
 20. The non-transitory memory elementof claim 16, wherein the instructions are executable by the processingelement to cause the UE to detect that the signal is a synchronizationsignal associated with the second RAT by using time domain x-correlationbetween the signal and one or more possible complex-valued mathematicalsequences.